General Asylum: REVIEW: Rogue Audio 120 Magnum mono blocks Amplifier (Tube) by The Killer Piglet

Model:	120 Magnum mono blocks
Category:	Amplifier (Tube)
Suggested Retail Price:	$3495
Description:	120 Watts per channel (ultra-linear moce) OR 75 Watts per channel (triode mode)
Manufacturer URL:	Rogue Audio
Manufacturer URL:	Rogue Audio

Review by The Killer Piglet ( A ) on June 15, 2002 at 17:55:29
IP Address: 66.21.192.176

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for the 120 Magnum mono blocks

Ok, fellows, this is my first shot at a review.Please be gentle (just kidding, flame away).
Oh, and sorry for the odd formatting; please suggest an AA friendly HTML editor. Front Page is not the way to go!
The amps
Rogue M120 Magnum Monoblocks, heavy SOB's.
Most of the weight is clearly on the power supply. A very good thing, I think.
They are plain looking boxes, no wood, gold plating, or any such sort of badging on them.
Another good thing, itâ€™s clear were the money went.
Tubes are out of harms way, in the back, protected by a metal grid. A VERY good thing.
Amps are sitting on the floor, not stands.

Time and Music
This review covers a period of 3 months. Listened to amps during all times of day, night, moods, weather, and whatever other intangibles you may wish to imagine.
Usually put 40 to 50 hours per week of listening.
Music covered all kinds, but or particular regulars are Cuban and Classic Rock. Both of these styles demand a lot of speed, in particular the Cuba "tres" guitar and "clave" percussion sticks.
Hereâ€™s "tres" primer, for the curious (a must for guitar fans):
tres
Here's a half dozen titles to give you some idea:
Beatles: Abbey Road, Sgt. Pepper
Led Zeppelin: I-IV
Pink Floyds: WYWH, DSOTM, The Wall

Estudiantina Invasora ("son" septet - tres, percussion, trumpets, trombone, asst. percussions, vocals): Music from Oriente de Cuba
Estrellas de Areito: Los Heroes (members vary, "son" septet base with piano, violins, bass, vocals)
Eliades Ochoa: A Una Coqueta (traditional "son" quartet - tres, percussions, vocals)

Listening Impressions
Compared with my previous amp, the Spectron Musician 2, I found them to be much more detailed.
The bass, surprisingly, was much stronger. I expected the tubes to be weaker in the bass.
The highs are very crisp, but not rolled off, and they are not metallic as
in the solid state amp.
Listening to guitar chords, it is now possible to clearly hear the chord as
a collection of individual strings rather and as a conglomerate single
merged sound, and the small sounds made by fingers on the guitar neck as
they lift or roll on the string can also be noticed. Each string now plays
and decays on it's own.
Listening to the old Trio Matamoros light up the tres becomes hypnotizing!
The organ note that's driven through Pink Floyd's Mother reveals itself as rising and dropping musical wave, unlike the single monotone sound presented by the ss amp (my wife pointed this out firs time she heard it).
Sibilance dropped dramatically compared with the ss amp, both for male and
female vocals.
All the sounds, both instrumental and vocal, exhibited greater texture and
fuller body, occupying a more defined space.
You can actually get a sense of how close the musicians are to each other,
and a real sense of the scale of the stage.
It is possible to listen to these amps for very long periods of time without any fatigue or ringing in the ears. Listening session of 6 to 10 hours (don't ask) can attest to that fact!
Most important, they do bring out much more emotion from the music. Now I understand what the big hoopla is about tubes.
Modes
The above comments refer to the amps in ultralinear mode.
We switched to triode for a period of one week. While there was a certain greater fullness to some of the sound, but the amps simply fell apart as soon as the music grew demanding. There was lack of speed, and a fuzziness to percussions. Drums sounded limp, and "claves" sound like two bread stick getting smacked. Electric guitars dissolved into mush, and the fast notes of the tres blurred.
Heart's Magic Man lost all of the impact of the drums, and my wife asked to make sure that I mentioned that the Beatles I am the Walrus sounded "distorted." She's right.
OK, so they're not very good in triode.
Tubes
I changed the controller tubes from the stock Philips to Telslovak tubes,
and while these did not change the tone of the music they slightly improved
on the imaging ad the soundstage.
Changing the stock EH6550's with Svetlana 6550'c produced quite a remarkable result. These amps are my first experience with tubes, and I was really (pleasantly) surprised at how much effect changing the tubes had. It was like replacing the amps. I do not mean to im[ply the EH's are bad tubes; 2 of the 3 months of this review period the EH's were in place.
The 6550c's just game me more of what I wanted: power, speed, resolution; and less of what I did not want: heat (I'd say they run at least 75% less heat).
Power
Amps are on dedicated lines, one pwer amp. Replaced stock PC's with Virtual Dynamics Cryo Power 2's. Changing cords resulted in a bit less noise, greater fullness in particularly from the mid-range down.
Odd and Ends
My understanding is that Mark O'Brien is a great person to deal with. On
this regard, I can only say that I asked a question via email and he
responded promptly and to the point.
I had one small problem, were the left amp was sounding very loose and
fluttery on the bass. I opened the amp up, and noticed two of the fuses were
not quite blown but still seemed a bit ragged. I replaced them and the amp
sounded fine from that point on.
These amps suffer from a ground loop. I tried everything (and I mean everything, as can be attested by some of the folks here whoâ€™ve helped like Steve Eddy) to track this down. No luck, cheater plugs it is.
They also suffer from RFI. You have to be very close to the speakers, and the room has to be very quite, but I hear a radio station!

Product Weakness: Noise from RFI and ground loop. Triode mode more show that go.
Product Strengths: Smooth, powerful, hefty power supply, just more emotional, money went into the substance, not the packaging.

Associated Equipment for this Review:
Amplifier:	Rogue M120 Magnum Monoblocks, Spectron Musician 2
Preamplifier (or None if Integrated):	Adcom GFP750
Sources (CDP/Turntable):	Sonye333ES--> DIP---> EVS Modded Link DAC w/custom PS
Speakers:	VSA VR-4's
Cables/Interconnects:	AP Oval 9's and Copper Ovla. Homegrown audio Silver Lace
Music Used (Genre/Selections):	Cuban, Classic Rock, Blues, Pop (in that order)
Room Size (LxWxH):	20 x 18 x 8
Room Comments/Treatments:	curtains, foam, sofa
Time Period/Length of Audition:	3 months
Other (Power Conditioner etc.):	60 amp dedicated panle;acme cry recp.
Type of Audition/Review:	Product Owner

Product Weakness:	Noise from RFI and ground loop. Triode mode more show that go.
Product Strengths:	Smooth, powerful, hefty power supply, just more emotional, money went into the substance, not the packaging.